Swiveling Roll Bar

ABSTRACT

The invention relates to a swivelable roll bar, in particular for construction vehicles, with two vertical carriers, each of which has a pair of spars, whereby in each, one spar is connected swivelably through a link joint with the another spar, and the link joint comprises a lock and a stop. The stop consists of a joint stiffener, which is built as an extension of one spar and partially grips about the end of the other. In addition to that, the lock has a continuously adjustable final control element, with which the joint stiffener can be braced against the other spar. With the grip about the other spar, the flexural strength of the link joint of the swivelable roll bar is increased. Further, the bracing of the joint stiffener against the other spar eliminates the play in the link joint. The joint stiffener is preferably built as a U-shaped tubular segment that is attached to the latter as an extension of the spar.

The invention relates to a swiveling roll bar for vehicles, especiallyfor construction vehicles, with two vertical carriers, each one of whichhas one pair of spars, which are connected with each other throughswivelable link joints. Further, the link joints have both a lock aswell as a stop, which limit the swivel area of the roll bar.

Work vehicles, especially construction vehicles, are often equipped withrollover protective fixtures and roll bars, which are fixed on thevehicle frame and extend upwards, to protect the operator in case of aoverturning of the vehicle. If the work vehicle is equipped with adriver's cabin, the roll bar is normally integrated in the driver'scabin. However, if the work vehicle is furnished without a driver'scabin, the roll bar is normally built separately, whereby the roll baris normally built as a U-shaped bar, whose free ends are fixed on thevehicle frame and whose cross members are essentially arranged above thehead of the operator. Due to this, the roll bar is frequently that partof the vehicle that stretches farthest upwards.

Such an upward jutting roll bar can be disadvantageous, for example,during transport of the vehicle or during its operation.

To overcome this problem, roll bars equipped with folding mechanisms areknown, which allow swinging away of the upper portion of the roll bar soas to reduce the height of the work vehicle. In general, these foldingmechanisms have locks, with which the upper segment of the roll bar isarrested in a up-swung state against the lower stationary segment of theroll bar. Swiveling roll bars are known, in which the upper swivelingsegment is connected with the lower, stationary segment by means of twobolts. Here one bolt works as a hinge, which is built stationary betweenboth the segments. The other bolt can be removed and thus allowsswiveling away of the upper segment. Here, the locking bolt is parallelto the swivel axis of the hinge.

The disadvantage thereby is that such a catch has some play due to thebolting and that the upper segment of the roll bar can swing out underoperation related vibrations. Moreover, such a connection is difficultto manufacture.

To overcome this problem there are constructions, in which the uppersegment of the roll bar is arrested through several screw connections,instead of through one bolt. The disadvantage thereby is that theremoval of the screws to unswing the upper segment of the roll bar ispossible only by using tools. Further, the screws are removed completelyto swivel back the upper segment of the roll bar and can be lost easily.In addition to that, the screw connection must be made with theprespecified clamping torque and hence can be carried out only bytrained personnel.

In the event of an overturn of the work vehicle, massive forces andmoments arise, which work on the roll bars and must be absorbed by thevertical spars. Buckling, bending or breaks can occur in the area of thejoint connection between the upper and the lower segments of the rollbar, since in general it is this part of the roll bar, which can leastabsorb the forces.

The underlying task posed by invention is therefore to prepare aswiveling roll bar, especially for construction vehicles, which exhibitsan simple built, whose link joints have high stiffness, and thus canabsorb massive forces, and whose upper, swiveling segment can lockagainst the lower, solid segment without play.

This task is solved in the invention in that the stop of the link jointconsists of a link joint stiffener, which on its part consists of anextension of one spar of the spar pair and one end of the spar graspsthe other spar of the spar pair partly. Further, the lock has acontinuously adjustable final control element, with which the jointstiffener can be braced against the other spar.

Advantageous embodiments of the invention are stated in the subordinateclaims.

Due to the fact that the extension of one spar partially grips an end ofthe other spar, an inflexible connection results between the two sparsin locked state. This significantly improves the ability of the linkjoint to absorb forces, and with that, the likelihood of a buckling,bending or breaking is reduced.

As the joint stiffener grips the other spar, it is possible to tightenthe joint stiffener against the other spar using a final controlelement. The tightening eliminates the play in the connection of theupper and the lower segment of the roll bar and thus prevents theswinging away of the upper segment of the roll bar in case ofvibrations. It is of advantage if a continuously adjustable finalcontrol element is built with integration in the link joint, so that thefinal control element cannot be lost when the lock is released.

In a further advantageous development of the invention, the lock is soarranged that its line of action lies in the swivel plane of the spar.Thus the final control element essentially acts diagonally to the swivelaxis and is not parallel to swivel axis as in the hitherto knownembodiments, so that greater tension is generated when locking, whichincreases the stiffness of the link joint.

It is of advantage, if the joint stiffener is constructed as a U-shapedreceiver, so that a strong gripping of the other spar is ensured.Preferably, the U-shaped receiver is designed as a tubular segment,which is open on one side in the longitudinal direction. Further, thejoint stiffener can be produced from a separate work piece that is fixedon one spar. This has the advantage that both the standard spars as wellas the standard tube segments can be used, which further simplifies themanufacture and assembly of the device.

In a further embodiment, the U-shaped receiver exhibits a stationaryconnection with a spar. Preferably, the connection is produced bywelding. This stationary type of connection increases the receivingcapacity of the link joint of the bending moments.

It is of advantage, if the link joint comprises a hinge, whereby amovable part of the hinge is built with a joint stiffener and the otherpart of the hinge is built as a hinge bearing, which is fixed on theother spar. With this arrangement, one spar is arranged with a recessbetween the hinge and thus also from the swivel axis of the link joint,due to which the upper segment of the roll bar can be swiveled away overthe vertex. Due to the slightly forward inclined position of the uppersegment of the roll bar resulting from this, the area over which theoperator is protected in case of an overturn is increased.

In an especially preferred embodiment, the joint stiffener completelygrips three sides of the other spar. This three-sided grip furtherincreases the stiffness of the link joint. Preferably, the jointstiffener is so arranged that its open side corresponds to the side ofthe link joint nearest to the hinge.

In a further embodiment, the final control element is constructed as aclamping screw. Preferably, the lock comprises a clamping bolt, which isarranged between the joint stiffener and the screw head and exhibits anopening, through which the threading of the clamping screw is arranged.It is preferable further, if the joint stiffener exhibits a recess inthe area of the clamping bolt. Thereby the recess is designed in such afashion that the clamping bolt of the clamping screw presses against theboundary of the recess. If the clamping screw is loosened, the clampingbolt can be brought into a position, in which it overlaps the recess, sothat the joint stiffener is released. On one hand, the tension resultingfrom the planar support of the clamping bolt can be distributed betteron the joint stiffener and on the other hand the clamping screw and theclamping bolt remain firmly connected with the link joint when loosened,so that they cannot be lost.

It is of advantage, if the clamping screw is constructed as a tommyscrew, so that no tool is required to tighten the joint stiffeneragainst the other spar.

In a further advantageous embodiment, the lock is constructed as aneccentric clamp. This embodiment is relatively simple to handle andrequires lesser effort for tightening the joint stiffener against theother spar. Further, the eccentric clamp is fastened on the other spar,so that this locking device is not lost in released state.

In an especially preferred embodiment, the lock has a two-armed swivelbolt, whereby the final control element of the lock is arranged on onearm. The final control element is preferably built as a clamping screwor a stop bolt. The swivel bolt is thereby so arranged that the armwithout the final control element, in case the upper segment of the rollbar is swung high completely, can be swiveled over and away from thejoint stiffener. In that state, the final control element is above theother spar. Therefore, due to the fastening of the swivel bolt on theother spar, it cannot be lost even in released state.

In a further preferable embodiment, the joint connection is constructedwith elastic bearing support. Thereby, the elastic bearing element ispreferably arranged between the hinge axis and the other spar. Onswinging up the upper segment of the roll bar, the joint stiffenerpresses against the end of the other spar, due to which the elasticbearing element is pressed together and pre-stress is generated. Thispre-stress leads to further improvement in the stiffness of the linkjoint.

Preferred embodiments of the invention are explained below in moredetail on the basis of the attached drawings. The drawings show:

FIG. 1 A side view of a roller without driver's cabin, with a swivelingroll bar both in the arrested and in the swiveled down state;

FIG. 2 A side view of a swiveling roll bar with swivel bar lock in thelocked state;

FIG. 3 A side view of the swiveling roll bar with swivel bar lock inFIG. 2 in down swung state;

FIG. 4 A perspective view of a link joint of a swiveling roll bar witheye bolt/clamp bolt lock in locked state;

FIG. 5 A perspective view of a link joint of a roll bar with swivel boltlock in locked state;

FIG. 6 A side view of a link joint of a swiveling roll bar, with aneccentric clamp as the lock, in locked state; and

FIG. 7 A cross section through a link joint of a swiveling roll bar withelastic bearing and an eccentric clamp as lock.

In the various embodiments according to the invention shown in thefollowing figures, the same components are indicated with the samereference signs.

FIG. 1 shows the side view of a cylinder 10 with a swiveling roll bar11, which has a stationary spar 12 and a swiveling spar 13. The roll bar11 is displayed not only in the locked but also in the down-swung state.The stationary spar 12 is fixed with the cylinder frame of the cylinder10 by means of bolt connections 14.

As it can be seen in FIG. 1, a link joint 15 is attached at the end theswivelable spar 13. The joint stiffener 15 consists, in the shownexample, of a U-shaped tubular segment, whereby the U-shaped tubularsegment 15 is so arranged that its open side corresponds to that side ofthe roll bar 11, on which the hinge 16 is attached. The U-shaped tubularsegment 15 is welded with the swivelable spar 13 and is connected withthe hinge 16, so that the U-shaped tubular segment 15, together with thewelded, upper, swivelable hinge 13, can swivel about the hinge 16. Thehinge 16 is welded with the stationary spar 12.

In the up-swung state of the swivel able hinge 13, due to the lock 17,the U-shaped tubular segment 15 braces against the stationary hinge 12.The lock 17 is so arranged, that it acts in the swivel plane of the rollbar 11, due to which the bracing of the U-shaped tubular segment 15 withthe stationary spar 12 is increased. In the example shown, the lock isbuilt with a tommy screw 18 and a clamping bolt 19. The tommy screw 18enables easy handling during the locking and releasing of the swivelablespar 13.

FIG. 2 shows the side view of a swivelable roll bar 11 in locked state.The lock 17 consists of a tommy screw 18, which is fastened to a swivelbar 20. The swivel bar 20 is swivelable about a strap hinge 21, which onits part is firmly fastened to a stationary hinge 12. The swivel bar isthereby so arranged that it can swivel about the lower end of theU-shaped tubular segment 15. When the swivel bar 20 swivels about thelower end of the U-shaped tubular segment 15, it can be braced againstthe stationary spar 12 by tightening the tommy screw 18, with which theroll bar 11 is locked.

In FIG. 3, a side view of the roll bar of FIG. 2 is shown, whereby thelock 17 is released and the swivelable hinge 13 is swung down.

In FIG. 4, a perspective view of a section of a swivelable roll bar 11in locked state is shown. The lock 17 consists of a clamping bolt 19 andan eye bolt 23. The U-shaped tubular segment 15 shows a recess 22, whichis at the lower end of the U-shaped tubular segment in the region of thelock 17. Both the clamping bolt 19 as well as the recess 22 haverectangular shape. Their dimensions match each other in such a fashionthat in crosswise position, the clamping bolt has contact with theU-shaped tubular segment 15 and the latter braces against the stationaryhinge 12 on tightening the eye bolt 23. If the eye bolt 23 is released,the clamping bolt 19 can be swung by about 90°, so that it can thenmatch the recess 22, and the U-shaped tubular segment 15, together withthe swivelable hinge 13, can be released.

In FIG. 5 a perspective view of a part of a swivelable roll bar 11 inlocked state is shown. The lock 17 consists of a two-arm swivel bar 24,which has, on one arm, clamping screw/stop bolts built as a clampingscrew grip 25. The swivel bar 24 is connected with the stationary hinge12 through the bolt 26, built almost at the center. Thereby the boltconnection 26 is so constructed that the swivel bar 24 can be rotatedabout the bolt. In locked state, the free arm of the swivel bar 24 isturned about the lower end of the U-shaped tubular segment 15, so thatthe other arm, on which the clamping screw grip 25 is attached, is abovethe stationary hinge 12. By tightening the clamping screw grip 25, thefree arm of the swivel bar 24, is pressed against the U-shaped tubularsegment 15, due to which it braces against the stationary hinge 12.

In FIG. 6, the side view of a part section of a swivelable roll bar 11in locked state is shown. The lock 17 consists of an eccentric clamp 27,which is attached to the hinge 12. The eccentric clamp 27 has a handle28, which is connected with an eccentric clamping element 29. Further,the eccentric clamp 27 can swivel about the swivel hinge 30, above whichit is fastened at the lower spar 12. In the locked state, the eccentricclamp 27 is swiveled about the lower part of the U-shaped tubularsegment 15 and the grip 28 is folded up, till it touches the U-shapedtubular segment 15. By folding the handle 28 up, the eccentric clampingelement 29 is pressed against the lower part of the U-shaped tubularsegment 15, so that it is braced against the lower hinge 12. To releasethe lock, the handle 28 is folded down, due to which the eccentricclamping element 29 is released, the eccentric clamp 27 swings down andthe U-shaped tubular segment 15, together with the swivelable spar 13,is released.

In FIG. 7 a cross section in the region of the link joint of aswivelable roll bar 11 in locked state is shown. The lock 17 isconstructed as an eccentric clamp 27. The embodiment according to theinvention shown in FIG. 7 has a buffer 31 made from an elastic material,which is arranged between the hinge 16 and the stationary spar 12. Inthe example shown in

FIG. 7, the buffer 31 made from an elastic material is embodied as anelastic cuff, which is put through the hinge 16. On folding theswivelable hinge 13 up (not shown here), the U-shaped tubular segment 15is pressed against the stationary spar 12. Just before the area of theU-shaped tubular segment 15 and the stationary spar 12 come to rest, awedge-like action takes place, due to which the buffer 31 is pressedtogether and the hinge 16 is pre-stressed.

1-14. (canceled)
 15. A swivelable roll bar with two vertical carriers,comprising: a first spar; a second spar; and a link joint, swivalablyconnecting the first spar to the second spar, including: a stopincluding a joint stiffener, rigidly attached to the first spar andpivotally attached to the second spar, and adapted to partly surroundthe second spar, the joint stiffener having a recess, and a lock havinga swivelable bracket connected via a hinge with the second spar and acontinuously adjustable actuating element, wherein the swivelablebracket locks the joint stiffener by swiveling over a part of the jointstiffener and releases the joint stiffener by swiveling to a position torelease the joint stiffener.
 16. The swivelable roll bar of claim 15,wherein the joint stiffener can be braced with the actuating elementsubstantially transversally to the swiveling axis with the first spar.17. The swivelable roll bar of claim 15, wherein the swivelable bracketis a swivelbar.
 18. The swivelable roll bar of claim 15, wherein theactuating element is a clamping screw.
 19. The swivelable roll bar ofclaim 18, wherein the clamping screw is arranged as a tommy screw. 20.The swivelable roll bar of claim 18, wherein the actuating element is aneccentric clamp.
 21. The swivelable roll bar of claim 18, wherein thelock comprises a handle.
 22. The swivelable roll bar of claim 18,wherein the joint stiffener consists of a U-shaped receptacle.
 23. Theswivelable roll bar of claim 22, wherein the U-Shaped receptacle isattached to the second spar in a stationary manner.
 24. The swivelableroll bar of claim 18, wherein the joint stiffener grips three sides ofthe first spar.
 25. The swivelable roll bar of claim 18, wherein thelink joint is held elastically, with an elastic bearing being arrangedin such a way that, on bracing, the joint stiffener is pressed againstthe first spar.
 26. A swivelable roll bar with two vertical carriers,comprising: a first spar; a second spar; and a link joint, swivalablyconnecting the first spar to the second spar, including: a stopincluding a joint stiffener, rigidly attached to the first spar andpivotally attached to the second spar, and adapted to partly surroundthe second spar, the joint stiffener having a recess, and a lock havinga two-arm swivel bar connected approximately centrally via a boltconnection with the second spar and a continuously adjustable actuatingelement being arranged on one arm of the swivel bar, wherein the otherarm of the swivel bar can be swiveled beyond the joint stiffener, withthe arm without the actuating element pressing against the jointstiffener to lock the joint stiffener, and wherein the joint stiffenercan be braced with the actuating element substantially transversally tothe swiveling axis with the first spar.
 27. The swivelable roll bar ofclaim 26, wherein the actuating element is a clamping screw of a detentpin.
 28. The swivelable roll bar of claim 26, wherein the actuatingelement is a grip clamping screw.
 29. The swivelable roll bar of claim26, wherein the lock comprises a handle.
 30. The swivelable roll bar ofclaim 26, wherein the joint stiffener consists of a U-shaped receptacle.31. The swivelable roll bar of claim 30, wherein the U-Shaped receptacleis attached to the second spar in a stationary manner.
 32. Theswivelable roll bar of claim 26, wherein the joint stiffener grips threesides of the first spar.
 33. The swivelable roll bar of claim 26,wherein the link joint is held elastically, with an elastic bearingbeing arranged in such a way that, on bracing, the joint stiffener ispressed against the first spar.